Preserved, deteriorated, and premorbidly impaired patterns of intellectual ability in schizophrenia.

Ammari, Narmeen; Heinrichs, R. Walter; Pinnock, Farena; Miles, A. A.; Muharib, Eva; Vaz, Stephanie McDermid

doi:10.1037/neu0000026

Cited by 23 publications

(23 citation statements)

References 171 publications

(274 reference statements)

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“…On the other hand, 30.5% of patients had an intact cognitive function. This finding is higher than previous studies that reported 19–28% of patients with psychosis found to have an intact cognitive function . This discrepancy may be due to the difference in duration of follow‐up, cognitive assessment tools, use of composite score, and level of cognitive function at baseline.…”

Section: Discussioncontrasting

confidence: 76%

Long‐term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings

Islam

Habtewold

et al. 2018

Acta Psychiatr Scand

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ObjectiveThis study aimed to assess the heterogeneity and stability of cognition in patients with a non‐affective psychotic disorder and their unaffected siblings. In addition, we aimed to predict the cognitive subtypes of siblings by their probands.MethodAssessments were conducted at baseline, 3 and 6 years in 1119 patients, 1059 siblings and 586 controls from the Genetic Risk and Outcome of Psychosis (GROUP) study. Group‐based trajectory modeling was applied to identify trajectories and clustered multinomial logistic regression analysis was used for prediction modeling. A composite score of eight neurocognitive tests was used to measure cognitive performance.ResultsFive stable cognitive trajectories ranging from severely altered to high cognitive performance were identified in patients. Likewise, four stable trajectories ranging from moderately altered to high performance were found in siblings. Siblings had a higher risk of cognitive alteration when patients’ alteration was mild (OR = 2.21), moderate (OR = 5.70), and severe (OR = 10.07) compared with patients with intact cognitive function. The familial correlation coefficient between pairs of index patients and their siblings was 0.27 (P = 0.003).ConclusionsThe cognitive profiles identified in the current study might be suitable as endophenotypes and could be used in future genetic studies and predicting functional and clinical outcomes.

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Section: Discussioncontrasting

confidence: 76%

Long‐term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings

Islam

Habtewold

et al. 2018

Acta Psychiatr Scand

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“…In addition, a premorbid–current ability discrepancy score was created by transforming the Reading standard score into a T score and subtracting the MCCB composite T score from this value. Similar discrepancy scores have been used to index premorbid–current ability differentials by Ammari et al (2014) , Badcock et al (2005) , Harvey et al (2006) and O’Connor et al (2012) . Clinical state and symptom severity were measured with the Positive and Negative Syndrome Scale (PANSS; Opler et al, 1999 ).…”

Section: Methodsmentioning

confidence: 99%

“…For example, an average-range IQ may not represent normal cognition if performance prior to illness onset was above average. Proxy measures of premorbid ability like reading skill reveal declines when compared with current ability in many schizophrenia patients ( Ammari et al, 2014 , Weickert et al, 2000 ). It follows that differences in estimated premorbid ability may exist between patients and controls even when there are no differences in current ability.…”

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confidence: 99%

Neurocognitive normality in schizophrenia revisited

Heinrichs

Pinnock

Muharib

et al. 2015

Schizophrenia Research: Cognition

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The validity and significance of normal range neurocognition in schizophrenia remain unclear and controversial. We assessed whether normal range patients and controls demonstrate evidence of decline relative to premorbid ability and differ in performance profiles across measures, including those external to the normality criterion. In addition, we compared below normal range healthy control participants with patients at the same ability level. Performance normality was defined as a MATRICS Consensus Cognitive Battery (MCCB) composite T score between 40 and 60. Patients (n = 17) and controls (n = 24) meeting the criterion were compared on MCCB domain scores and on independent measures of reading ability, probabilistic and social reasoning. Patients (n = 19) and controls (n = 20) scoring below 40 on the MCCB composite were compared on the same set of measures. Cognitively normal range patients and controls did not differ on estimated premorbid ability or decline and differed only on the Processing Speed domain of the MCCB. Performance did not differ across other domains or on social and probabilistic reasoning tasks. Cognitively below normal range patients and controls showed marked discrepancies between premorbid and current ability, but there were no group differences. In addition, below normal range groups did not differ on any MCCB domain score or in terms of external cognitive measures. Cognitively normal range schizophrenia patients may be largely indistinguishable from normal range controls, with the exception of processing speed performance. More typical schizophrenia patients below the normal range may be indistinguishable from low-performing controls even in terms of processing speed.

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“…The degree of intelligence decline in patients with schizophrenia is typically classified into three intellectual levels [18,23,47,69,71,72,73,74,75,76,77]:Deteriorated group: patients with a difference of 10 points or more between premorbid IQ and present IQ;Preserved group: patients with a difference of less than 10 points between premorbid IQ and present IQ (premorbid IQ above 90);Compromised group: patients with a difference of less than 10 points between premorbid IQ and present IQ (premorbid IQ below 90).…”

Section: Intelligence Decline In Schizophreniamentioning

confidence: 99%

Genetic Overlap between General Cognitive Function and Schizophrenia: A Review of Cognitive GWASs

Ohi

Sumiyoshi

Fujino

et al. 2018

IJMS

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General cognitive (intelligence) function is substantially heritable, and is a major determinant of economic and health-related life outcomes. Cognitive impairments and intelligence decline are core features of schizophrenia which are evident before the onset of the illness. Genetic overlaps between cognitive impairments and the vulnerability for the illness have been suggested. Here, we review the literature on recent large-scale genome-wide association studies (GWASs) of general cognitive function and correlations between cognitive function and genetic susceptibility to schizophrenia. In the last decade, large-scale GWASs (n > 30,000) of general cognitive function and schizophrenia have demonstrated that substantial proportions of the heritability of the cognitive function and schizophrenia are explained by a polygenic component consisting of many common genetic variants with small effects. To date, GWASs have identified more than 100 loci linked to general cognitive function and 108 loci linked to schizophrenia. These genetic variants are mostly intronic or intergenic. Genes identified around these genetic variants are densely expressed in brain tissues. Schizophrenia-related genetic risks are consistently correlated with lower general cognitive function (rg = −0.20) and higher educational attainment (rg = 0.08). Cognitive functions are associated with many of the socioeconomic and health-related outcomes. Current treatment strategies largely fail to improve cognitive impairments of schizophrenia. Therefore, further study is needed to understand the molecular mechanisms underlying both cognition and schizophrenia.

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Preserved, deteriorated, and premorbidly impaired patterns of intellectual ability in schizophrenia.

Cited by 23 publications

References 171 publications

Long‐term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings

Long‐term cognitive trajectories and heterogeneity in patients with schizophrenia and their unaffected siblings

Neurocognitive normality in schizophrenia revisited

Genetic Overlap between General Cognitive Function and Schizophrenia: A Review of Cognitive GWASs

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